Infancy, childhood, and puberty on the Silk Road revealed with isotopic analysis of incremental dentine

Abstract

Childhood is a unique phase in human life history, in which newborns are breastfed and weaned, and are progressively familiarized to adult diets. By investigating dietary changes from infancy to adolescence, valuable information regarding past cultural behaviors and aspects of human lives can be explored and elucidated. Here, in conjunction with published isotopic results of serial dentine (n = 21) from Yingpan Man, new δ13C and δ15N results are obtained from 172 samples of incremental dentine from 8 teeth of 8 individuals of the Yingpan cemetery, located in Xinjiang, China. The δ13C values range from – 18.2 to – 14.6‰ with a mean ± SD value of – 16.3 ± 0.9‰, and the δ15N results range between 13.4 and 19.9‰ with a mean ± SD value of 16.0 ± 1.4‰. This indicates that the childhood diets were mixtures of C3 and C4 dietary resources and were clearly influenced by breastfeeding and weaning practices. In particular, the findings indicate that there were significant inter-individual differences in terms of the timing and duration of breastfeeding and weaning practices as well as childhood dietary practices at Yingpan. For instance, three individuals were exclusively breastfed after birth, while, two individuals and Yingpan Man were not. In addition, the post-weaning diets of most Yingpan individuals were relatively stable, but one individual and Yingpan Man displayed clear evidence of increased consumption of C4 foods, likely millet, during late and post-weaning periods. Further, 7 individuals had unique dietary changes between 9 to 14 years old. Potential factors related to this are presented from the perspective of changes in social roles that might be caused by their early participation in the social division of labor or puberty and marriage.

Life history of a high‐class noblewoman from the late Shu state in the Chengdu Plain during the Eastern Zhou period (770–221 BC): Childhood stresses and stable life

“…Compared with the results of our previous studies on life histories of Late Neolithic populations from the Chengdu Plain, M154 was weaned approximately 1 year earlier than that of Gaoshan humans (c. 2500-2000 BC, mean age at weaning completion: 3.6 ± 0.9 years, Yi et al, 2021Yi et al, , 2018 and suffered physiological stresses after weaning but recovered quickly. Previous studies have showed that individual life history is closely related to identity status, social and cultural background, and so on (Wang, Wei, et al, 2022;Laffoon et al, 2018;Eerkens et al, 2017;Tsutaya et al, 2016;Frei et al, 2015;Lamb et al, 2014;Knudson et al, 2012) and that humans have learned to respond to early-life stress and have adaptability and resistance to stress (McFadden & Oxenham, 2020;Temple, 2014). The change pattern in δ 15 N dent values of M154 on both occasions (seen above in stage b and d in Figure 5) was a rapid rise and fall within a short duration (less than 1 year), suggesting that she possesses a good ability to respond to stress, which may be related to her higher identity status, allowing her to have easier access to resources during early growth and development and to be better cared for.…”

“…However, human lifestyles in late Shu culture period have not been extensively explored, as previous studies mainly focused on the Late Neolithic to early Shu culture stages (Lin et al, 2022; Yi et al, 2018; Yi et al, 2021). In recent years, various aspects of an individual's life from birth to death have begun to be revealed at a finer resolution by conducting multi‐isotope analyses of skeletal and dentin serial sections or hair keratin representing different life stages (Wang, Wei, et al, 2022; Fernández‐Crespo et al, 2020; Kaupová et al, 2020; Yi et al, 2019; Laffoon et al, 2018; Eerkens et al, 2017; Tsutaya et al, 2016; Frei et al, 2015; Lamb et al, 2014; Knudson et al, 2012). In particular, combination of morphological variation and pathological features observed from skeletal and dental remains with stable isotope analyses of incremental dentine samples provides more vivid information for understanding changes in health and dietary patterns of individuals at different stages of the life course (Crowder et al, 2019; D'Ortenzio et al, 2015; O'Donoghue et al, 2021; Sandberg et al, 2014; Walter et al, 2020).…”

“…However, human lifestyles in late Shu culture period have not been extensively explored, as previous studies mainly focused on the Late Neolithic to early Shu culture stages (Lin et al, 2022;Yi et al, 2018;Yi et al, 2021). In recent years, various aspects of an individual's life from birth to death have begun to be revealed at a finer resolution by conducting multi-isotope analyses of skeletal and dentin serial sections or hair keratin representing different life stages (Wang, Wei, et al, 2022;Fernández-Crespo et al, 2020;Kaupová et al, 2020;Yi et al, 2019;Laffoon et al, 2018;Eerkens et al, 2017;Tsutaya et al, 2016;Frei et al, 2015;Lamb et al, 2014;Knudson et al, 2012).…”

Diets, stress, and disease in the Etruscan society: Isotope analysis and infantile skeletal palaeopathology from Pontecagnano (Campania, southern Italy, 730–580 BCE)

“…While reconstruction of weaning timing through stable nitrogen isotope analysis from bulk bone collagen has some issues (due to tissue turnover rates, enrichment factors, differential isotopic composition of weaning foods compared to adult foods, on this topic (e.g., [128][129][130]), the application of incremental dentine is, instead, widely accepted as a routine method for more robust investigations of past breastfeeding, weaning and childhood dietary practices (e.g., [96,97,102,104,[131][132][133][134][135]).…”